Question of the Hour: Does COVID-19 Infection Make You Immune?

April 10th, 2020

By Gary Evans, Medical Writer

In the rapid emergence of the COVID-19 pandemic comes much that is unknown beyond the general assumption that there is no preexisting human immunity to this novel coronavirus.

The question of the hour — which will determine the progression of the outbreak in the coming weeks and months — is whether those who survive infection with SARS-CoV-2 generate sufficient antibodies to be immune for some period of time.

“That is certainly the hope,” says William Schaffner, MD, a veteran infectious disease physician and professor of preventive medicine at Vanderbilt University. “If you look at the human coronaviruses — the ones that cause the common colds — you do next get strain immunity, but it begins to wane fairly quickly after about a year. But that kind of immunity would be terribly important in blunting a resurgence of this virus in the fall. It might be a bridge to the time we can get a vaccine deployed.”

Anthony Fauci, MD, director of the National Institutes of Health, National Institute of Allergy and Infectious Diseases, also recently commented on this issue in an interview. “Right now, we don’t think that this [SARS-CoV-2] is mutating to the point of being very different,” Fauci said. “So, we are making a reasonable assumption that this virus is not changing very much. If you get infected in February or March — and then recover — then next September or October, I believe that person is going to be protected. We are not 100% sure. But I think that is a reasonable assumption.”

Antibody tests are now coming to the market that could detect if someone has generated an immune response to a prior COVID-19 infection.

“There are a lot companies trying to get them out so they could be used for finger pricks with little devices and read within minutes,” Schaffner says. “This would be extraordinarily helpful in managing the healthcare and first responder environment. Then actually going out in communities and making an assessment about what proportion of the population is immune — it could help us get people with prior experience with the virus back to work.”

These tests certainly have great promise to impact the coronavirus response, but the antibody diagnostics must be carefully validated before they are widely distributed, Fauci emphasized.

“There have been international incidents where a country has ordered millions of these tests from another country — only to find that they don’t work,” he said. “We have to validate these tests — that’s absolutely critical. Otherwise you will go down a path that will be very misleading."

Viewing the pandemic writ large, Fauci said the public health system may have become a victim of its own success — with antibiotics, vaccines, and antiviral therapies creating the illusion that the U.S. healthcare system was ready for any threat.

“We let it slip, and boy, this should be a lesson for the future,” he said. “My hope is that when we get out of this — which we will — we will take a really good look at the long-term investments in the public health infrastructure. We should never again be in a position like this and have to scramble in response. This is historic. We all know the history of what happened in 1918, when we did not have hardly any of the interventions or the capabilities that we have now. You see what is happening in New York City, that is beyond sobering — that is really terrible."

For more on this story, see the May 2020 issue of Hospital Infection Control & Prevention.